/*
 * Copyright 2005 The Apache Software Foundation
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.mybatis.generator.internal.db;

/**
 * Typesafe enum of known database dialects
 * 
 * @author Jeff Butler
 */
public enum DatabaseDialects
{
    
    DB2("VALUES IDENTITY_VAL_LOCAL()"), //$NON-NLS-1$
    MYSQL("SELECT LAST_INSERT_ID()"), //$NON-NLS-1$
    SQLSERVER("SELECT SCOPE_IDENTITY()"), //$NON-NLS-1$
    CLOUDSCAPE("VALUES IDENTITY_VAL_LOCAL()"), //$NON-NLS-1$
    DERBY("VALUES IDENTITY_VAL_LOCAL()"), //$NON-NLS-1$
    HSQLDB("CALL IDENTITY()"), //$NON-NLS-1$
    SYBASE("SELECT @@IDENTITY"), //$NON-NLS-1$
    DB2_MF("SELECT IDENTITY_VAL_LOCAL() FROM SYSIBM.SYSDUMMY1"), //$NON-NLS-1$
    INFORMIX("select dbinfo('sqlca.sqlerrd1') from systables where tabid=1"); //$NON-NLS-1$
    
    private String identityRetrievalStatement;
    
    /**
     *  
     */
    private DatabaseDialects(String identityRetrievalStatement)
    {
        this.identityRetrievalStatement = identityRetrievalStatement;
    }
    
    public String getIdentityRetrievalStatement()
    {
        return identityRetrievalStatement;
    }
    
    /**
     * @param database
     * @return the database dialect for the selected database. May return null
     *         if there is no known dialect for the selected db
     */
    public static DatabaseDialects getDatabaseDialect(String database)
    {
        DatabaseDialects returnValue = null;
        
        if ("DB2".equalsIgnoreCase(database)) { //$NON-NLS-1$
            returnValue = DB2;
        }
        else if ("MySQL".equalsIgnoreCase(database)) { //$NON-NLS-1$
            returnValue = MYSQL;
        }
        else if ("SqlServer".equalsIgnoreCase(database)) { //$NON-NLS-1$
            returnValue = SQLSERVER;
        }
        else if ("Cloudscape".equalsIgnoreCase(database)) { //$NON-NLS-1$
            returnValue = CLOUDSCAPE;
        }
        else if ("Derby".equalsIgnoreCase(database)) { //$NON-NLS-1$
            returnValue = DERBY;
        }
        else if ("HSQLDB".equalsIgnoreCase(database)) { //$NON-NLS-1$
            returnValue = HSQLDB;
        }
        else if ("SYBASE".equalsIgnoreCase(database)) { //$NON-NLS-1$
            returnValue = SYBASE;
        }
        else if ("DB2_MF".equalsIgnoreCase(database)) { //$NON-NLS-1$
            returnValue = DB2_MF;
        }
        else if ("Informix".equalsIgnoreCase(database)) { //$NON-NLS-1$
            returnValue = INFORMIX;
        }
        
        return returnValue;
    }
}
